Frequency of left mainstem disease in patients with unstable angina undergoing coronary angiography.

Objective: To determine the frequency of left main stem disease (LMS) in patients presenting with unstable angina (UA) undergoing coronary angiography (CA). Study Design: Cross-sectional Study. Setting: Department of Cardiology, Rehmatul-lil-Alameen Postgraduate Institute of Cardiology, PESSI, Lahore. Period: 1st August 2025 to 31st January 2026. Methods: A total of 199 patients were enrolled in the study based on non-Probability consecutive sampling. The study population comprised all adult patients (aged ≥18 years; both genders) admitted to the cardiology department with a clinical diagnosis of unstable angina who subsequently underwent coronary angiography. The data was stratified (With LMS & without LMS disease) according to age, gender, BMI, duration of disease, family history, comorbidities (diabetes, hypertension & hyperlipidemia) and smoking status. Post-stratification chi-square test was applied to identify association between stratified groups. Statistical analysis was performed using SPSS Version 27. A p-value of ≤0.05 was considered statistically significant. Results: The mean age of the study population was 58.4 ± 10.2 years (range; 36-69 years). One hundred & thirty (65.3%) male; 69 (34.7%) females. The most common cardiovascular risk factor was hypertension, present in 110(55.3%) patients, followed by diabetes mellitus; 91(45.7%) patients, current smoking; 65(32.7%) patients, positive family history; 60(30.1%), dyslipidemia; 43(21.6%) & Obesity (BMI>30); 39(19.6%) patients. Patients with LMS disease were significantly older with 86.9% having age >50 years (p <0.001). Additionally, the prevalence of diabetes 69.6% vs 42.6 %; p =0.027), positive family history (65.2% vs 19.8 %; p <0.001), hyperlipidemia (43.8% vs 18.7%; p=0.015), duration of disease >10 years (78.3% vs. 21.6%; p<0.001) and concomitant multi-vessel disease (78.3% vs. 21.6%; p <0.001) was significantly higher among patients with LMS disease. Conclusion: This study demonstrates that left main stem (LMS) disease is present in a clinically significant proportion of patients presenting with unstable angina (UA) who undergo coronary angiography. The frequency observed in this study (11.5%) underscores the importance of maintaining a high index of suspicion for LMS involvement in this high-risk patient population.